CHAPTER 5B SEDIMENT COMPARTMENTS

CHAPTER 5B SEDIMENT COMPARTMENTS-ROMPIN DISTRICT
2A5.9.2 Summerset Coast
This sector begins at the Pekan-Rompin district boundary and ends at the road junction along the
track that leads to the Recreation Forest. The beaches vary from severely eroding in the area of
Summerset resort to actively accreting towards the south. No beach profiles were surveyed but a
sketch was done in front of the southernmost chalet and a beach quality was administered in front
of the resort
Summerset North
At Summerset North, the beach is retreating and threatening resort structures (Figure 5-110). The
beach condition has changed recently, as the beach used to be wide and attractive. Now some
portions of the beach are littered with fallen trees and wave overwash is common all along the
coast. The hinterland has been disturbed and drains collect water from the swamps for discharge.
Oddly a discharge point for treated water for the resort is updrift of the resort which means that
the effluents after discharge will cross in front of the resort. The discharge outlet was blocked by
drifting sands on the 2000 aerial photograph.
Figure 5-110. Summerset North
The setback of the building is now less than 60m (Figure 5-111). As the shoreline retreats
towards the hotel and chalets some kind of response is expected from the resort operators. The
beach in front of the hotel was assessed for quality and surprisingly was rated as of good quality
despite the erosion. The beach is of inherent good quality but care must be taken to maintain it.
The narrow beach makes it difficult for holiday makers to use the popular dune buggies to
explore the beach except during low tide as the beach is often straddled by fallen trees.
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Figure 5-111. Summerset Coast
A sketched profile in front of the southern-most chalet shows the structure built on stilts without
any disturbance to the permatang surface and sands and strand materials were being washed
towards the chalets by storm waves (Figure 5-112). The coastline is scarped and in front is a short
beach face with crescent swash bars. The permatang plain is low-lying and subjected to over
topping by storm waves.
Figure 5-112. Schematic coastal profile of Summerset coast
The various features are illustrated in planform in Figure 5-113. There were two series of
overwash and in front of the beach was a series of crescent shaped bars, exposed during low tide,
migrating downcoast. Locally, inter-tidal sands were turning greenish, caused by eutrophication
which suggests that the discharging effluents or soakaways were not fully treated.
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Figure 5-113. Planform view of coastal features in Summerset
Selected feature of the northern portion of Summerset are shown in Figure 5-114.
1. Overwash sands
2. Crescent shaped sand bars
4. Green sands- a sign of eutrophication
3. Eroding coast with scarp and fallen trees
Figure 5-114. Coastal characteristics of Summerset Coast
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Summerset Mid Section
The middle portion of Summerset coast covers the beach from in front of Kem Summerset as well
as an undeveloped accreting coast to the south. The coastline in front of Kem Summerset is
severely eroding and a sharp scarp has formed behind a very narrow beach (Figure 5-115). The
camp is setback on the permatang far inland though and is not under immediate threat. South of
the canal, the coast is mainly undeveloped although land has been alienated and some of them are
planted with coconut trees. The coastal vegetation is very sparse taking on the appearance of a
woodland. The beach is actively accreting from sands eroded from upcoast and the lower beach
has well developed cusps. Young casuarinas have colonized the newly accreted sands. The
coastal track runs close to the each in places but is safe from erosion because of the advancing
coast. However, as the sands move downcoast, the beach here will narrow and shoreline retreat
towards the coastal track may follow.
A. Kem Summerset eroding coast
B. Accreting Coast south of Kem Summerset
Figure 5-115. Summerset-mid section
Summerset South
Along the southern portion of Summerset South, the beach widens further. The permatang plain is
mainly undeveloped except for a small house and big house with interesting design occupying
one of the lots planted with coconut trees (Figure 5-116). Heathy woodlands cover the permatang
deposits and swamps occupy the infilled lagoon behind.
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Figure 5-116. Southern boundary Summerset Coast
The 2005 oblique aerial photograph illustrates the accreting condition of the coast very well
(Figure 5-117), with young casuarinas regenerating along the upper beach and juvenile casuarinas
behind.
Figure 5-117. Accreting Summerset South coast
The swamps and woodlands are part of a recreational forest which extends from near the coast to
the main road. The forests are near pristine with interesting wild life (Figure 5-118). The isolated,
accreting beach was assessed as very good and was ranked jointly first with the beach farther to
the south at Pasir Panjang.
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A. Accreting sand along the coas
B. Recreational forest and wild chicken
Figure 5-118. Selected features of interest along Summerset South
2A5.9.3 Pasir Panjang Coast
The beginning of the Pasir Panjang coast also marks the beginning of the Rompin spit and the
sector ends at the narrowest point of the spit at Kampung Pasir Panjang. The coast differs from
Sebayan and Summerset in that the whole coastal to Sungai Rompin is mainly composed of beach
ridges, without large intervening swamps. Except for Kampung Pasir Panjang, the coast is mainly
undeveloped. However it lies between Lanjut and Summerset and has similar natural attractions
to the coasts that have been developed for tourism. The beach narrows in a southerly direction
and the coastal track runs just inland of the beach (Figure 5-119). The backing permatang plain
serves as a large storage of sands and if allowed to retreat will help to stabilize episodes of
erosion. Hence, it would be prudent to preserve a buffer zone and not alienate land too close to
the present beach into private ownership.
Figure 5-119. Northern portion Pasir Panjang Coast
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At Pasir Panjang are several small resorts and places of accommodation catering to local tourists
(Figure 5-120). Basic amenities are provided for picnickers. Most of the resorts are behind the
coastal track and not beach-front properties. An exception is De Rhu Ombak Village, and along
its seaward boundary are remains of built structures, which may be indicative of recent shoreline
retreat. The beach is wide though and along the lower beach are well developed beach cusps,
usually found on coasts with coarse beach sediments and exposed to bigger waves.
Figure 5-120. Pasir Panjang beach
Despite recent erosion, Pasir Panjang is an advancing coastline, as indicated by the presence of
several old scarps representing former coastlines behind the present beach (Figure 5-121). The
recently-formed beach ridges are covered by shady beach forest. The beach was assessed as being
very good, one of the two beaches of South Pahang in this category.
Figure 5-121. Advancing Pasir Panjang coast
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Selected coastal features of Pasir Panjang are shown in Figure 5-122. These are the high quality
beach along the whole sector and chalet developments.
1. North Pasir Panjang beach of high quality
2. Pasir Panjang beach of high quality
4. Beach front De Rhu Ombak Village
3. Rantau De Rhu
Figure 5-122. Coastal characteristics and development of Pasir Panjang Coast
2A5.9.4 Lanjut Coast
The southern end of Rompin spit of about 6 km long is described as Lanjut coast. A major portion
of the beach front is occupied by the integrated Lanjut Beach Resort. The buildings are set back
well behind the wide, attractive beach. Unfortunately rubbish brought down by Sungai Rompin is
strewn all over the coast and wind had blown the plastic materials inland. The strand materials of
styrofoam boxes, plastic bottles and other plastics, clearly seen on the aerial photographs have an
appearance of boulder revetment. The old Lanjut Town which was the end of the Rompin iron ore
railway was located here. The iron ore jetty has disappeared together with the railway line and the
locomotive which was once displayed in town. The stockpile of iron ore gas been flattened but
the presence of red earth marks their former position. Remains of an old airstrip can still be
observed on the ground. The area has been taken over by Lanjut Resort, and the landscape has
been modified with the construction of the golf course and the ponds to provide water for the
greens. The spit is generally wide but a narrow neck of just 300m wide at the middle portion of
this coast is highly vulnerable to breaching. The river side is being scoured by the meandering
river and will have to be defended to avoid breaching which will isolate the villages at the distal
end of the spit. Rompin is part of Malaysia’s history and the setting up of a museum here will
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help to keep the heritage alive. There is also the interesting story of how the locals which once
worked for the mine hasve adapted to a new lifelihood.
Lanjut coast is divided into a northern portion (the bulge on the spit), a middle portion (the
narrow neck of the spit) and a southern portion (distal end of spit).
Lanjut North
The bulge forms Lanjut North and except for the northernmost sector, the rest of the beach front
is occupied by Lanjut Resort (Figure 5-123). The beaches are wide but the land to the back is
highly vulnerable to wave overwash as evidenced by lines strand materials deposited inland. The
coast is also plagued by large quantities of flotsams, probably originating Sungai Rompin, which
eventually end upon the beach. Most of the permatang area to the back has been developed and
are now occupied by small coconut holdings and large market gardens.
Figure 5-123. Lanjut North Coast 2000 (Beginning of bulge)
A buffer zone separates the hotels and chalets from the sea and the coastal scenery is attractive
with beach forests and a clean beach in front of the resort area (Figure 5-124). Local net
fishermen work the nearshore areas and large quantities of non-commercial, small crabs are
netted and left to rot on the beach. The beach appears stable in contrast to the eroding beach in
front of Summerset resort. However, the beach could have been reshaped to make it more
attractive for resort guests.
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Figure 5-124. Lanjut Resort 2005
Analyses of coastline change revealed that the coastline has been advancing in front of the resort
and golf course and that land has not been lost to erosion (Figure 5-125). Access to the beach is
not restricted although there is a guard post leading to the resort and beach. This is probably
because the place is so isolated that it is assumed that only resort guests will use the road leading
to the beach. Lanjut Resort is also the home of wood ball and there is a serious attempt to
promote the sport
Figure 5-125. Advancing coast in front of Lanjut Resort and golf course
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A profile leveled from the scarp farther to the south near the golf course captures a retreating
coast with extensive wave overwash (Figure 5-126). In front of the scarp is a narrow berm
dropping to a concavo-convex beach face of 8.7 degrees. The width of the beach from scarp to
still water level just above mean sea level is about 30 m wide and can be considered as average
for the mainland coast of South Pahang. The beach sediments were coarse grained, moderately
sorted, negatively skewed and leptokurtic. The beach here was assessed as of marginal quality
when considering all parameters. The beach assessment was administered away from the main
resort area. It was eroding, dirty, uninteresting and full of insects. The beach in front of the resort
is of much higher quality. The dirty beach is also part of the resort beach front and guest when
exploring the beach will pass this sector. It makes sense to clean the whole beach front of the
resort area to make resort guests have a better impression of Lanjut beach.
LANP1
29 April 05, SWL
1 0
4
Concavo-convex Beach Slope
Veg. line and scarp
top
3.5
scarp bottom
3
Height in metre (RL)
bf begins, cusp
2.5
Beach face slope 8.7˚
2
1.5
HAT
HAT
MHHW
MHHW
1
0.5
bf ends swl
MSL
0
0
MSL
10
20
30
40
50
60
Distance in metre
Figure 5-126. LANP1
Selected features of the northern portion of Lanjut coast, shown in Figure 5-127, are contrasting
beach condition in front and away from the main resort area, uncollected overwash of fishing
stakes and other flotsams, and remains of netted, unwanted crabs left on the beach.
1. Beach in front of Lanjut Resort
2. Location LANP1, scarped coast
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4. Crab remains on the beach
3. Uncollected strand materials
Figure 5-127. Coastal characteristic of Lanjut North Coast
Lanjut Middle Portion
The narrow middle portion of the spit is occupied by Lanjut golf course but along the narrow
neck, the land is undeveloped although land has been alienated into private ownership (Lot 2609).
In front of the golf course, the coast is fronted by reasonably wide beaches which show a
characteristic cusp formation (Figure 5-128). A belt of matured beach forest lies behind the beach
behind a low scarp, suggesting that the beach is retreating.
Figure 5-128. Lanjut coast middle portion occupied by golf course (beginning of neck)
At the narrow and vulnerable neck, a sharp scarp defined the landward margin of the beach which
shows the characteristic cusp formation along the lower beach (Figure 5-129). Aerial
photographic evidence suggest a series of cusps occupying different elevations on the beach,
related to different monsoon conditions, the higher cusp formed during the northeast monsoon
when the mean sea level is higher buy up to 40cm.
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Figure 5-129. Narrow neck of mid portion Lanjut coast
Lanjut South
The distal end contrasts greatly with the big spits to the north which are actively accreting and the
ends are composed of multiple recurves. The Rompin spit is not active and, in fact, the end is
being truncated by Sungai Rompin (Figure 5-130). It is cutting back and the scouring is made
worse by the Seratus foreland growing across the river mouth from the southern bank and
narrowing the entrance. On the 2000 aerial photograph, the truncation was very pronounced and
as Sungai Rompin forms a barrier to sediment transport across its mouth, sands were
accumulating on the updrift side to form a wide beach.
Figure 5-130. Lanjut South-distal end of truncated spit-2000
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However, on the 2005 oblique aerial photograph, the northern portion of the accreting beach
eroded badly and the beach forest was cut back and many trees toppled into the sea (Figure 5131). A bar was also extending down from the north to start protecting parts of the retreating
shores. A 2.5 ha piece of private land (Lot 2773) that juts out into the sea at the southern end of
the bar could have been eroded away. The onset of erosion and pattern of beach erosion and
accretion is highly dynamic, largely influenced by processes operating offshore and upcoast. This
makes predictions of coastline change hazardous. Under such a situation a precautionary principle
approach is recommended by creating a wide coastal buffer zone to allow the beach to retreat
without any socio-economic impacts and recover naturally.
Figure 5-131. Erosion and accretion at distal end of Rompin spit
A beach profile levelled at Bernas captured a scarped permatang plain with a narrow beach in
front, and a slightly convex beach slope of 8.2 degrees (Figure 5-132). The land surface stood at
more than one metre above HAT and should be free of tidal inundation. The beach sands were
medium grained, poorly sorted, nearly symmetrical and leptokurtic. The beach was assessed as
moderate in quality when considering all parameters
09 April 05, 1850
4
Slightly Convex Beach Slope
3.5
veg. line, scarp top
Height in metre (RL)
3
2.5
2
HAT
1.5
HAT
bf begins, scarp
bottom
MHHW
MHHW
1
Beach face slope 8.2˚
beach face
bf ends, swl
0.5
MSL
0
0
MSL
5
10
15
20
25
30
35
40
45
Distance in metre
Figure 5-132. BERP1 beach profile
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2A5.9.5 Tanjung Tengku Coast
The Tanjung Tengku coast covers the coast from the distal end of the spit to the Kampung
Tanjung Tengku village. The coast is technically inside the river mouth and more influenced by
the behaviour of Sungai Rompin (see Figure 5-118 for location). This is a critically eroding coast,
the shores attacked by river action combined with refracted waves entering the river mouth. The
soft coastal substrate of mud makes the construction of structures a problem and this is reflected
in the failing jetty and sea wall recently constructed. Currently there is an ongoing river mouth
improvement project but no activities were observed at Tanjung Tengku during a field visit. Up
river, geotubes had been emplaced along the river bank to protect a small cemetery. Remains of
the former iron ore stockpiles have turned the land surface red and previously, earth washed into
the sea have turned it red.
The history and impacts of erosion at Tanjung Tengku are described in detail in Chapter 7.
Analyses of coastline change on the distal end of the spit, shown in Figure 5-133, reveals that the
river side retreated and the ocean side advanced. Hence, private land was lost on the river side
(Lots 158, 162, 163, 161) and southern coast (Lot 176) but none on the ocean coast. The presence
of two coastlines on the cadastral map suggests that as the coast advanced on the ocean side, a 2.5
ha piece of land in front of the general alignment of alienated land was alienated into private
ownership (Lot 2773). Such land would be the first to be lost should there be any shoreline retreat.
Surprisingly the land on which the small resort stood and in which a seawall had been built to
protect the building did not lose any land as the wall was constructed along its property line.
Figure 5-133. Retreat along river side and advance along ocean side in distal end of Rompin spit
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A profile levelled from the mangroves across a sandy beach captured a low lying beach barely
above high spring tides with a flat beach of 4.1 degrees in front (Figure 5-134). The sands are
being washed into the backing mangroves. The whole beach system is submerged during HAT.
The beach sands were medium grained, poorly sorted, nearly symmetrical and platykurtic. The
beach was assessed as moderate in quality when considering all parameters. It is an interesting
beach, with backing mangroves and a river front but unfortunately the water is murky and when
the sand veneer is too thin, the underlying swamp deposits are exposed.
TUNP1
30 April 05, 0903
2.5
Slightly Concave Beach
berm
2
Height in metres (RL)
HAT
HAT
mangrove
bf begins,
strand
1.5
MHHW
MHHW
Beach face slope 4.1˚
1
0.5
bf ends, swl
MSL
0
0
MSL
10
20
30
40
50
60
Distance in metres
Figure 5-134. TUNP1 of low lying beach
Selected features of Tanjung Tengku coast are shown in Figure 5-135. These are the collapsing
bridge and mud coast, the river mouth beach and backing mangroves, river bank geotubes
protecting the cemetery and the failed sea wall in front of a small resort run by locals.
1. Failed bridge and mud coast
2. Tengku beach and mangroves
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4. Failed sea wall
3. Geotubes protecting cemetery
Figure 5-135.Coastal characteristics of Tengku coast
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